Started out clear yesterday. Below, an example of that completely clear sky in case you missed it.

10:06 AM. Clear skies are evident as we look in the general direction of Baja California. HOWEVER, note shallow smog plume exiting Tucson and flows northwestward across Continental Ranch over there by Twin Peaks where fellow University of Washington meteorologist, Mark Albright, lives.

I think it is interesting that Mark would chose to live as a snowbird in a smog plume rather than here in Catalina where that Tucson smog plume rarely strikes. Its pretty regular down there because the normal morning wind in Tucson is from the southeast and that wind shoves the urban smog over to Mark’s house on many cold mornings. Pretty funny, really.

Yesterday’s clouds

And, in those leading Cirrus clouds were some spectacular, stupefying really, complex patterns of cloud formation and and holes in them, ones like CM had never seen before except maybe that one time in Durango back in the 1970s. Here are some examples of those odd that were up there:

3:14 PM overview of Cirrocumulus and Cirrus clouds with oddities.3:14 PM Close up of previous cloud scene. Note all the weird stuff going on.3:22 PM. More oddities. Going crazy trying to understand what the HECK is going on!3:23 PM. Close up of rectangular “fringe.”

Started to breath a sigh of relief when this melange of complexity moved off rapidly worrying that someone might call and ask me to explain it. So, when some Cirrus uncinus and/or the rarely seen Cirrus castellanus came by I started to relax, feel confident again. Here are some of those pretty shots of little, icy clouds trailing light snow showers, likely, to repeat again, crystals called bullet rosettes. The ones in the part of the cloud from which they spew are likely tiny prisms, side planes, and tiny solid columns, thick, but tiny hexagonal plates with little fall speed, so those hang up there, while the favored ones in the best tiny updrafts in these clouds that resemble tiny glacial Cumulus clouds grow from those kind germ crystals into bullet rosettes, complicated crystals with multiple tiny columns sticking out of them. If you would like to read all about the crystals that form in high icy clouds like these you should spend some time browsing this paper, co-authored by the great John Hallett1 I really like footnotes–yes, of the Hallett and Mossop riming and splintering mechanism, discovered by them in 1974. Helped explain why there was a LOT of extra ice in clouds that shouldn’t have it.

Here’s one more weird scene in Cirrus before moving on to something explicable:

3:43 PM. Holes, plops of downward moving air amid the Cirrus/Cirrocumulus. But why so round?

Thankfully, here’s what transpired next at Cirrus levels:

4:02 PM. Cirrus uncinus (one with tufts or hooks at the top and long streamers of ice below them) followed the strangely patterned sky.4:03 PM. Look at all the larger ice crystals pouring out these little guys! Its amazing. Notice how FINE those strands are. Airborne work we did indicated that the cores were only a 5-20 meters wide!4:20 PM. Reminded me of a ballet the way the clouds and the streamers were arranged around one another.4:17 PM. Just a little before the dancing clouds came by, there toward the Gap was this CIrrus castellanus mimicry of a full grown Cumulonimbus capillatus (tuft in center of photo). Look, it even has a tiny anvil spreading out, to use the word “tiny” for the 18th time! How fun was that to see!

Of course, with all the patchy Cirrus around we were guaranteed a nice sunset and it did not disappoint:

5:29 PM. Sunset.

Today’s clouds

Heavy ice clouds, several kilometers thick at times. We call that kind of fray, often full sky-covering layer, Altostratus. Likely some Altocu around, too. Will look now and see if I see any of those latter ones. Oops, too dark.

With clouds kilometers thick, tops at Cirrus levels, you can expect to see virga, and the chance of a few “sprinkles-its-not-drizzle” later in the day. The whole progression of clouds can be seen from the U of AZ model output from last night in these forecast soundings for Tucson. As per usual, the bottoms get lower and lower as the day goes by, but are still up around 13, 000 feet above Catalina by around sunset. So, will be tough to get a drop to the ground before then. U of AZ mod thinks all measurable rain will be to the south of us. Oh, me.

BTW, and this is an embarrassment, it was asserted by this keyboard that rain would fall in November at the outset of the month. This is the last chance for that! Egad. But forgetting that possible gaffe, moving ahead anyway to what’s going to happen in December (of this year).

The storms way ahead, that is, ones in early December.

Those early December storms for us are coming and going in the WRF-GFS runs. But I am counting on rain here in early December myself due to an interpretation of those weird in so many ways, “spaghetti plots.” I think they’re showing, and continue to do so, significant troughs coming through the Southwest in early December.

The End

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1Later after the referenced paper above, and this is quite interesting, the great Hallett was to claim that me and Pete Hobbs had embarrassed2 the entire field of airborne researchers due to a paper published by us way back in 1983 (J. Hallett, 2008, communicated by him during his presentation at the Pete Hobbs Symposium Day of the American Meteorological Society, New Orleans.

2But it was a good embarrassment, not a bad one due to incompetence, I think.